OBJECTIVE： To observe the efficacy and related indicators of Kangfuxin lipid combined with lidocaine assisted with oxygen therapy on the efficacy and related indicators of patients with recurrent oral ulcer. METHODS： 80 patients with recurrent oral ulcer were randomly divided into control group （40 cases） and observation group （40 cases）. All patients were given oxygen therapy. Based on it， control group received Lidocaine hydrochloride gel 2 g， smearing and covering the mucosal ulceration surface， once a day. Observation group was additionally given Kangfuxin lipid 10 ml， taking after 5 min in mouth， no food and no gargling within 30 min， 3 times a day. The 2 groups were treated for 7 d. The clinical efficacy， ulcer healing time， and the levels of T lymphocyte subsets before and after treatment， recurrence of 6 months follow-up and the incidence of adverse reactions in 2 groups were observed. RESULTS： The total effective rate in observation group was significantly higher than control group， ulcer healing time was significantly shorter than control group， recurrence rate was significantly lower than control group， with statistical significance （P＜0.05）. After treatment， the levels of T lymphocyte subsets in 2 groups were significantly higher than before， and observation group was higher than control group， with statistical significances （P＜0.05）. And there was no significant difference in the incidence of adverse reactions in 2 groups （P＞0.05）. CONCLUSIONS： Kangfuxin lipid combined with lidocaine assisted with oxygen therapy shows significant efficacy in the treatment of recurrent oral ulcer， it can effectively relieve symptoms and signs， accelerate the healing process of ulcers， improve immune system function and reduce recurrence rate， with good safety.